The RFNM Interface is what connects the complicated bits in the motherboard to the daughterboards implementing specific applications.
You are encouraged to develop your own RFNM Daughterboard. To do so, you can use the Template Board as your starting point.
Functionality exposed to the daughterboards
We have two daughterboard interfaces, a Primary (also called RBA for Radio Board A in the schematics or code) and a Secondary (RBB).
The Primary is physically closer to the LA9310, and is intended to offer the highest performance. It is also the only daughterboard that can transmit data via the DACs, as the LA9310 only has one DAC I/Q interface.
The secondary is close to a MIPI DSI interface, that can be used to offer a future display daughterboard for a portable spectrum analyzer application.
Other than this, the functionality between the two connectors is mostly symmetrical. On each interface, we have:
- 2x I/Q ADC pairs, 4x differential ADCs.
- 1x I/Q DAC pair (only on Primary).
- 2x differential clocks directly from the Si5510 (up to 650 MHz fractional).
- LVDS interface for high speed RFIC communication.
- PPS input for synchronization (Time Appliance Project, only on Primary).
- SPI, I2C, GPIOs and CAN.
- Frontend latches.
The pinout is available here.